A cis-acting element in the 3′-untranslated region of human TNF-α mRNA renders splicing dependent on the activation of protein kinase PKR
A cis-acting element in the 3′-untranslated region of human TNF-α mRNA renders splicing dependent on the activation of protein kinase PKR
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DOI：
10.1101/gad.13.24.3280
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发表时间：
1999-12-15
影响因子：
10.5
通讯作者：
Kaempfer, R
中科院分区：
文献类型：
--
作者：
Osman, F;Jarrous, N;Kaempfer, R
我们报告了3 '-非翻译区在mRNA剪接控制中的作用，并表明人TNF-α 3' UTR具有顺式作用元件，该元件使前体转录物的剪接依赖于PKR的激活，PKR是磷酸化真核起始因子2（eIF 2）的RNA活化蛋白激酶。当这个元件，指定为2-APRE，是存在的，剪接变得敏感的抑制PKR抑制剂e-氨基嘌呤，或共表达的反显性负突变PKR。我们的研究结果表明，激活PKR是必要的mRNA剪接时，前体转录含有2-APRE和野生型PKR的表达增加，提高其剪接效率。因此，PKR作为反式作用因子响应2-APRE。2-APRE RNA形成稳定的17 bp茎环结构，并在体外强烈激活PKR，诱导eIF 2 α磷酸化。尽管其能够在剪接过程中激活PKR，但3' UTR内的2-APRE不影响转染细胞中所得TNF-α mRNA的翻译效率。PKR和3' UTR因此在mRNA剪接期间相互作用，以赋予对TNF-α基因表达的新型调节。
We report a role for the 3'-untranslated region in control of mRNA splicing and show that human TNF-alpha 3' UTR harbors a cis-acting element that renders splicing of precursor transcripts dependent on activation of PKR, the RNA-activated protein kinase that phosphorylates eukaryotic initiation factor 2 (eIF2). When this element, designated 2-APRE, is present, splicing becomes sensitive to inhibition by the PKR inhibitor e-aminopurine, or by coexpression of transdominant-negative mutant PKR. Our results reveal that activation of PKR is required for splicing of mRNA when precursor transcripts contain the 2-APRE and that increased expression of wild-type PKR enhances their splicing efficiency. Thus, PKR responds as trans-acting factor to the 2-APRE. 2-APRE RNA forms a stable, 17-bp stem-loop structure and strongly activates PKR in vitro, inducing eIF2 alpha phosphorylation. Despite its ability to activate PKR during splicing, the 2-APRE within the 3' UTR does not affect translation efficiency of the resulting TNF-alpha mRNA in transfected cells. PKR and the 3' UTR thus interact during mRNA splicing to confer a novel type of regulation on expression of the TNF-alpha gene.